A wintry pattern is expected to intensify across the northwestern United States and southern British Columbia as a series of storms lines up. A storm closing out this week will offer only a small indication of what the setup may deliver through much of December, including an elevated risk of flooding, mudslides and avalanches, AccuWeather meteorologists said. "A weak atmospheric river is expected to accompany the storm from Thursday night to Friday," AccuWeather Senior Meteorologist Brett